Method for Electrochemically Fabricating Three-Dimensional Structures Including Pseudo-Rasterization of Data

ABSTRACT

Some embodiments of the invention are directed to techniques for electrochemically fabricating multi-layer three-dimensional structures where selective patterning of at least one or more layers occurs via a mask which is formed using data representing cross-sections of the three-dimensional structure which has been modified to place it in a polygonal form which defines only regions of positive area. The regions of positive area are regions where structural material is to be located or regions where structural material is not to be located depending on whether the mask will be used, for example, in selectively depositing a structural material or a sacrificial material. The modified data may take the form of adjacent or slightly overlapped relative narrow rectangular structures where the width of the structures is related to a desired formation resolution. The spacing between centers of adjacent rectangles may be uniform or may be a variable. The data modification may also include the formation of duplicate copies of an original structure, scaled copies, mirrored copies, rotated copies, complementary copies, and the like.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.11/028,943 (Microfabrica Docket No. P-US131-A-SC), filed Jan. 3, 2005which in turn claims benefit of U.S. Provisional Patent Application No.60/534,185, filed Dec. 31, 2003. Theses referenced applications areincorporated herein by reference.

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to the field ofelectrochemical fabrication and the associated formation ofthree-dimensional structures (e.g. microscale or mesoscale structures).In particular, some embodiments of the invention relate to manipulationsof data representing one or more three-dimensional structures to derivecross-sectional data that includes boundaries that define regions ofpositive areas only and more particularly some embodiments are directedto deriving such data where the data takes the form of a plurality ofadjacent and similarly oriented, elongated rectangular structures.

BACKGROUND OF THE INVENTION

A technique for forming three-dimensional structures (e.g. parts,components, devices, and the like) from a plurality of adhered layerswas invented by Adam L. Cohen and is known as ElectrochemicalFabrication. It is being commercially pursued by Microfabrica® Inc.(formerly MEMGen Corporation) of Van Nuys, Calif. under the name EFAB®.This technique was described in U.S. Pat. No. 6,027,630, issued on Feb.22, 2000. This electrochemical deposition technique allows the selectivedeposition of a material using a unique masking technique that involvesthe use of a mask that includes patterned conformable material on asupport structure that is independent of the substrate onto whichplating will occur. When desiring to perform an electrodeposition usingthe mask, the conformable portion of the mask is brought into contactwith a substrate while in the presence of a plating solution such thatthe contact of the conformable portion of the mask to the substrateinhibits deposition at selected locations. For convenience, these masksmight be generically called conformable contact masks; the maskingtechnique may be generically called a conformable contact mask platingprocess. More specifically, in the terminology of Microfabrica® Inc.(formerly MEMGen Corporation) of Van Nuys, Calif. such masks have cometo be known as INSTANT MASKS™ and the process known as INSTANT MASKING™or INSTANT MASK™ plating. Selective depositions using conformablecontact mask plating may be used to form single layers of material ormay be used to form multi-layer structures. The teachings of the '630patent are hereby incorporated herein by reference as if set forth infull herein. Since the filing of the patent application that led to theabove noted patent, various papers about conformable contact maskplating (i.e. INSTANT MASKING) and electrochemical fabrication have beenpublished:

(1) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and P. Will,“EFAB: Batch production of functional, fully-dense metal parts withmicro-scale features”, Proc. 9th Solid Freeform Fabrication, TheUniversity of Texas at Austin, p 161, August 1998.

(2) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and P. Will,“EFAB: Rapid, Low-Cost Desktop Micromachining of High Aspect Ratio True3-D MEMS”, Proc. 12th IEEE Micro Electro Mechanical Systems Workshop,IEEE, P 244, January 1999.

(3) A. Cohen, “3-D Micromachining by Electrochemical Fabrication”,Micromachine Devices, March 1999.

(4) G. Zhang, A. Cohen, U. Frodis, F. Tseng, F. Mansfeld, and P. Will,“EFAB: Rapid Desktop Manufacturing of True 3-D Microstructures”, Proc.2nd International Conference on Integrated MicroNanotechnology for SpaceApplications, The Aerospace Co., April 1999.

(5) F. Tseng, U. Frodis, G. Zhang, A. Cohen, F. Mansfeld, and P. Will,“EFAB: High Aspect Ratio, Arbitrary 3-D Metal Microstructures using aLow-Cost Automated Batch Process”, 3rd International Workshop on HighAspect Ratio MicroStructure Technology (HARMST'99), June 1999.

(6) A. Cohen, U. Frodis, F. Tseng, G. Zhang, F. Mansfeld, and P. Will,“EFAB: Low-Cost, Automated Electrochemical Batch Fabrication ofArbitrary 3-D Microstructures”, Micromachining and MicrofabricationProcess Technology, SPIE 1999 Symposium on Micromachining andMicrofabrication, September 1999.

(7) F. Tseng, G. Zhang, U. Frodis, A. Cohen, F. Mansfeld, and P. Will,“EFAB: High Aspect Ratio, Arbitrary 3-D Metal Microstructures using aLow-Cost Automated Batch Process”, MEMS Symposium, ASME 1999International Mechanical Engineering Congress and Exposition, November,1999.

(8) A. Cohen, “Electrochemical Fabrication (EFABTM)”, Chapter 19 of TheMEMS Handbook, edited by Mohamed Gad-EI-Hak, CRC Press, 2002.

(9) Microfabrication—Rapid Prototyping's Killer Application”, pages 1-5of the Rapid Prototyping Report, CAD/CAM Publishing, Inc., June 1999.

The disclosures of these nine publications are hereby incorporatedherein by reference as if set forth in full herein.

The electrochemical deposition process may be carried out in a number ofdifferent ways as set forth in the above patent and publications. In oneform, this process involves the execution of three separate operationsduring the formation of each layer of the structure that is to beformed:

1. Selectively depositing at least one material by electrodepositionupon one or more desired regions of a substrate.

2. Then, blanket depositing at least one additional material byelectrodeposition so that the additional deposit covers both the regionsthat were previously selectively deposited onto, and the regions of thesubstrate that did not receive any previously applied selectivedepositions.

3. Finally, planarizing the materials deposited during the first andsecond operations to produce a smoothed surface of a first layer ofdesired thickness having at least one region containing the at least onematerial and at least one region containing at least the one additionalmaterial.

After formation of the first layer, one or more additional layers may beformed adjacent to the immediately preceding layer and adhered to thesmoothed surface of that preceding layer. These additional layers areformed by repeating the first through third operations one or more timeswherein the formation of each subsequent layer treats the previouslyformed layers and the initial substrate as a new and thickeningsubstrate.

Once the formation of all layers has been completed, at least a portionof at least one of the materials deposited is generally removed by anetching process to expose or release the three-dimensional structurethat was intended to be formed.

The preferred method of performing the selective electrodepositioninvolved in the first operation is by conformable contact mask plating.In this type of plating, one or more conformable contact (CC) masks arefirst formed. The CC masks include a support structure onto which apatterned conformable dielectric material is adhered or formed. Theconformable material for each mask is shaped in accordance with aparticular cross-section of material to be plated. At least one CC maskis needed for each unique cross-sectional pattern that is to be plated.

The support for a CC mask is typically a plate-like structure formed ofa metal that is to be selectively electroplated and from which materialto be plated will be dissolved. In this typical approach, the supportwill act as an anode in an electroplating process. In an alternativeapproach, the support may instead be a porous or otherwise perforatedmaterial through which deposition material will pass during anelectroplating operation on its way from a distal anode to a depositionsurface. In either approach, it is possible for CC masks to share acommon support, i.e. the patterns of conformable dielectric material forplating multiple layers of material may be located in different areas ofa single support structure. When a single support structure containsmultiple plating patterns, the entire structure is referred to as the CCmask while the individual plating masks may be referred to as“submasks”. In the present application such a distinction will be madeonly when relevant to a specific point being made.

In preparation for performing the selective deposition of the firstoperation, the conformable portion of the CC mask is placed inregistration with and pressed against a selected portion of thesubstrate (or onto a previously formed layer or onto a previouslydeposited portion of a layer) on which deposition is to occur. Thepressing together of the CC mask and substrate occur in such a way thatall openings, in the conformable portions of the CC mask contain platingsolution. The conformable material of the CC mask that contacts thesubstrate acts as a barrier to electrodeposition while the openings inthe CC mask that are filled with electroplating solution act as pathwaysfor transferring material from an anode (e.g. the CC mask support) tothe non-contacted portions of the substrate (which act as a cathodeduring the plating operation) when an appropriate potential and/orcurrent are supplied.

An example of a CC mask and CC mask plating are shown in FIGS. 1A-1C.FIG. 1A shows a side view of a CC mask 8 consisting of a conformable ordeformable (e.g. elastomeric) insulator 10 patterned on an anode 12. Theanode has two functions. FIG. 1A also depicts a substrate 6 separatedfrom mask 8. One is as a supporting material for the patterned insulator10 to maintain its integrity and alignment since the pattern may betopologically complex (e.g., involving isolated “islands” of insulatormaterial). The other function is as an anode for the electroplatingoperation. CC mask plating selectively deposits material 22 onto asubstrate 6 by simply pressing the insulator against the substrate thenelectrodepositing material through apertures 26 a and 26 b in theinsulator as shown in FIG. 1B. After deposition, the CC mask isseparated, preferably non-destructively, from the substrate 6 as shownin FIG. 1C. The CC mask plating process is distinct from a“through-mask” plating process in that in a through-mask plating processthe separation of the masking material from the substrate would occurdestructively. As with through-mask plating, CC mask plating depositsmaterial selectively and simultaneously over the entire layer. Theplated region may consist of one or more isolated plating regions wherethese isolated plating regions may belong to a single structure that isbeing formed or may belong to multiple structures that are being formedsimultaneously. In CC mask plating as individual masks are notintentionally destroyed in the removal process, they may be usable inmultiple plating operations.

Another example of a CC mask and CC mask plating is shown in FIGS.1D-1F. FIG. 1D shows an anode 12′ separated from a mask 8′ that includesa patterned conformable material 10′ and a support structure 20. FIG. 1Dalso depicts substrate 6 separated from the mask 8′. FIG. 1E illustratesthe mask 8′ being brought into contact with the substrate 6. FIG. 1Fillustrates the deposit 22′ that results from conducting a current fromthe anode 12′ to the substrate 6. FIG. 1 G illustrates the deposit 22′on substrate 6 after separation from mask 8′. In this example, anappropriate electrolyte is located between the substrate 6 and the anode12′ and a current of ions coming from one or both of the solution andthe anode are conducted through the opening in the mask to the substratewhere material is deposited. This type of mask may be referred to as ananodeless INSTANT MASK™ (AIM) or as an anodeless conformable contact(ACC) mask.

Unlike through-mask plating, CC mask plating allows CC masks to beformed completely separate from the fabrication of the substrate onwhich plating is to occur (e.g. separate from a three-dimensional (3D)structure that is being formed). CC masks may be formed in a variety ofways, for example, a photolithographic process may be used. All maskscan be generated simultaneously, prior to structure fabrication ratherthan during it. This separation makes possible a simple, low-cost,automated, self-contained, and internally-clean “desktop factory” thatcan be installed almost anywhere to fabricate 3D structures, leaving anyrequired clean room processes, such as photolithography to be performedby service bureaus or the like.

An example of the electrochemical fabrication process discussed above isillustrated in FIGS. 2A-2F. These figures show that the process involvesdeposition of a first material 2 which is a sacrificial material and asecond material 4 which is a structural material. The CC mask 8, in thisexample, includes a patterned conformable material (e.g. an elastomericdielectric material) 10 and a support 12 which is made from depositionmaterial 2. The conformal portion of the CC mask is pressed againstsubstrate 6 with a plating solution 14 located within the openings 16 inthe conformable material 10. An electric current, from power supply 18,is then passed through the plating solution 14 via (a) support 12 whichdoubles as an anode and (b) substrate 6 which doubles as a cathode. FIG.2A, illustrates that the passing of current causes material 2 within theplating solution and material 2 from the anode 12 to be selectivelytransferred to and plated on the cathode 6. After electroplating thefirst deposition material 2 onto the substrate 6 using CC mask 8, the CCmask 8 is removed as shown in FIG. 2B. FIG. 2C depicts the seconddeposition material 4 as having been blanket-deposited (i.e.non-selectively deposited) over the previously deposited firstdeposition material 2 as well as over the other portions of thesubstrate 6. The blanket deposition occurs by electroplating from ananode (not shown), composed of the second material, through anappropriate plating solution (not shown), and to the cathode/substrate6. The entire two-material layer is then planarized to achieve precisethickness and flatness as shown in FIG. 2D. After repetition of thisprocess for all layers, the multi-layer structure 20 formed of thesecond material 4 (i.e. structural material) is embedded in firstmaterial 2 (i.e. sacrificial material) as shown in FIG. 2E. The embeddedstructure is etched to yield the desired device, i.e. structure 20, asshown in FIG. 2F.

Various components of an exemplary manual electrochemical fabricationsystem 32 are shown in FIGS. 3A-3C. The system 32 consists of severalsubsystems 34, 36, 38, and 40. The substrate holding subsystem 34 isdepicted in the upper portions of each of FIGS. 3A to 3C and includesseveral components: (1) a carrier 48, (2) a metal substrate 6 onto whichthe layers are deposited, and (3) a linear slide 42 capable of movingthe substrate 6 up and down relative to the carrier 48 in response todrive force from actuator 44. Subsystem 34 also includes an indicator 46for measuring differences in vertical position of the substrate whichmay be used in setting or determining layer thicknesses and/ordeposition thicknesses. The subsystem 34 further includes feet 68 forcarrier 48 which can be precisely mounted on subsystem 36.

The CC mask subsystem 36 shown in the lower portion of FIG. 3A includesseveral components: (1) a CC mask 8 that is actually made up of a numberof CC masks (i.e. submasks) that share a common support/anode 12, (2)precision X-stage 54, (3) precision Y-stage 56, (4) frame 72 on whichthe feet 68 of subsystem 34 can mount, and (5) a tank 58 for containingthe electrolyte 16. Subsystems 34 and 36 also include appropriateelectrical connections (not shown) for connecting to an appropriatepower source for driving the CC masking process.

The blanket deposition subsystem 38 is shown in the lower portion ofFIG. 3B and includes several components: (1) an anode 62, (2) anelectrolyte tank 64 for holding plating solution 66, and (3) frame 74 onwhich the feet 68 of subsystem 34 may sit. Subsystem 38 also includesappropriate electrical connections (not shown) for connecting the anodeto an appropriate power supply for driving the blanket depositionprocess.

The planarization subsystem 40 is shown in the lower portion of FIG. 3Cand includes a lapping plate 52 and associated motion and controlsystems (not shown) for planarizing the depositions.

Another method for forming microstructures from electroplated metals(i.e. using electrochemical fabrication techniques) is taught in U.S.Pat. No. 5,190,637 to Henry Guckel, entitled “Formation ofMicrostructures by Multiple Level Deep X-ray Lithography withSacrificial Metal layers”. This patent teaches the formation of metalstructure utilizing mask exposures. A first layer of a primary metal iselectroplated onto an exposed plating base to fill a void in aphotoresist, the photoresist is then removed and a secondary metal iselectroplated over the first layer and over the plating base. Theexposed surface of the secondary metal is then machined down to a heightwhich exposes the first metal to produce a flat uniform surfaceextending across the both the primary and secondary metals. Formation ofa second layer may then begin by applying a photoresist layer over thefirst layer and then repeating the process used to produce the firstlayer. The process is then repeated until the entire structure is formedand the secondary metal is removed by etching. The photoresist is formedover the plating base or previous layer by casting and the voids in thephotoresist are formed by exposure of the photoresist through apatterned mask via X-rays or UV radiation.

Even though electrochemical fabrication as taught and practiced to date,has greatly enhanced the capabilities of microfabrication, and inparticular added greatly to the number of metal layers that can beincorporated into a structure and to the speed and simplicity in whichsuch structures can be made, room for enhancing the state ofelectrochemical fabrication exists.

SUMMARY OF THE INVENTION

It is an object of some embodiments of the invention to provide animproved method for deriving data necessary to define cross-sectionalconfigurations of structures or groups of structures to be formed.

It is an object of some embodiments of the invention to providesimplified data manipulation techniques for defining cross-sectionaldata representing layers of structure that are to be formed.

Other objects and advantages of various embodiments of the inventionwill be apparent to those of skill in the art upon review of theteachings herein. The various embodiments of the invention, set forthexplicitly herein or otherwise ascertained from the teachings herein,may address one or more of the above objects alone or in combination, oralternatively may address some other object of the invention ascertainedfrom the teachings herein. It is not necessarily intended that allobjects be addressed by any single aspect of the invention even thoughthat may be the case with regard to some aspects.

In a first aspect of the invention, a process for forming a multilayerthree-dimensional structure, includes: (a) providing data descriptive ofthe three-dimensional structure; (b) processing the data to derivecross-sectional data descriptive of a plurality of cross-sections of thethree-dimensional structure; (c) processing the cross-sectional data toderive modified cross-sectional data including polygons, where eachindividual polygon encloses only a positive area; (d) using the modifiedcross-sectional data in a process for forming a patterned adhered mask;(e) forming and adhering a layer of material to a substrate, wherein thesubstrate may include one or more previously deposited materials; (f)repeating the forming and adhering operation a plurality of times tobuild up a three-dimensional structure from a plurality of adheredlayers, wherein the formation of at least one layer includes using thepatterned adhered mask to pattern the substrate or previously depositedmaterial.

In a second aspect of the invention, a process for modifying asubstrate, includes: (a) providing data descriptive of a modification tobe made to a substrate; (b) processing the data to derivecross-sectional data descriptive of the modification of the substrate;(c) processing the cross-sectional data to derive modifiedcross-sectional data including polygons, where each individual polygonencloses only a positive area; (d) using the modified cross-sectionaldata in a process for forming a patterned adhered mask; (e) modifyingthe substrate using the patterned adhered mask.

In a third aspect of the invention, a process for forming a multilayerthree-dimensional structure, includes: (a) providing cross-sectionaldata descriptive of a plurality of cross-sections of thethree-dimensional structure; (c) processing the cross-sectional data toderive modified cross-sectional data including polygons, where eachindividual polygon encloses only a positive area; (d) using the modifiedcross-sectional data in a process for forming a patterned adhered mask;(e) forming and adhering a layer of material to a substrate, wherein thesubstrate may include one or more previously deposited materials; (f)repeating the forming and adhering operation a plurality of times tobuild up a three-dimensional structure from a plurality of adheredlayers, wherein the formation of at least one layer includes using thepatterned adhered mask to pattern the substrate or previously depositedmaterial.

In a fourth aspect of the invention, a process for modifying asubstrate, includes: (a) providing cross-sectional data descriptive ofthe modification of the substrate; (c) processing the cross-sectionaldata to derive modified cross-sectional data including polygons, whereeach individual polygon encloses only a positive area; (d) using themodified cross-sectional data in a process for forming a patternedadhered mask; (e) modifying the substrate using the patterned adheredmask.

Further aspects of the invention will be understood by those of skill inthe art upon reviewing the teachings herein. Other aspects of theinvention may involve apparatus that can be used in implementing one ormore of the above method aspects of the invention. These other aspectsof the invention may provide various combinations of the aspects,embodiments, and associated alternatives explicitly set forth herein aswell as provide other configurations, structures, functionalrelationships, and processes that have not been specifically set forthabove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C schematically depict side views of various stages of a CCmask plating process, while FIGS. 1D-1G schematically depict a sideviews of various stages of a CC mask plating process using a differenttype of CC mask.

FIGS. 2A-2F schematically depict side views of various stages of anelectrochemical fabrication process as applied to the formation of aparticular structure where a sacrificial material is selectivelydeposited while a structural material is blanket deposited.

FIGS. 3A-3C schematically depict side views of various examplesubassemblies that may be used in manually implementing theelectrochemical fabrication method depicted in FIGS. 2A-2F.

FIGS. 4A-4I schematically depict the formation of a first layer of astructure using adhered mask plating where the blanket deposition of asecond material overlays both the openings between deposition locationsof a first material and the first material itself.

FIG. 5 provides a block diagram of a process for forming athree-dimensional structure according to a first embodiment of theinvention including the manipulation of data representing the structureto obtain data suitable for use in creating one or more photomasks thatwill be used in the fabrication of the structure.

FIG. 6 provides a block diagram detailing an exemplary set of operationsthat may be performed in completing the data manipulation operation ofFIG. 5 including a cross-sectioning operation, an indicating operation,and a data production operation.

FIGS. 7A-7C provide block diagrams of three examples of how theoperations of FIG. 6 may be supplemented by additional operations toallow photomasks to be produced which have patterning corresponding to aplurality of copies of the structure or structures to be formed.

FIG. 8 provides a block diagram showing two examples of how theindicating operation of FIG. 6 may be implemented.

FIG. 9 provides a block diagram showing an example of how the dataproduction operation of FIG. 6 may be implemented along with two examplealternatives on how polygon boundaries may relate to the data lines fromwhich they are derived.

FIG. 10 provides a schematic illustration of a top view of an examplecross-sectional configuration of two three-dimensional structures thatare to be formed.

FIGS. 11A-11D provide schematic illustrations of top views of variousstages of the process of FIG. 9 where the regions defined to includepositive areas are those that are occupied by structure to be formed.

FIG. 12 provides a schematic illustration of a top view of the structureof FIG. 11A where the polygons are shown as having a width that issomewhat larger than the spacing between successive polygons.

FIGS. 13A-13D provide schematic illustrations of top views of variousstages of the process of FIG. 9 where the regions defined to includepositive areas are those that are outside the regions to be occupied bystructure to be formed.

FIGS. 14A-14B provide schematic illustrations of top views of a pair ofstructures which are to be duplicated multiple times in a mask that isto be produced and where the duplications may include one or morerotations, scaling variations, mirroring operations, complementingoperations, and the like.

FIG. 15 provides a block diagram of a process for forming athree-dimensional structure according to a second embodiment of theinvention including the manipulation of data representing the structureto obtain data suitable for use in creating one or more masks that maybe used in selectively patterning a substrate or previously depositedmaterial during the fabrication of the structure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1A-1G, 2A-2F, and 3A-3C illustrate various features of one form ofelectrochemical fabrication that are known. Other electrochemicalfabrication techniques are set forth in the '630 patent referencedabove, in the various previously incorporated publications, in variousother patents and patent applications incorporated herein by reference,still others may be derived from combinations of various approachesdescribed in these publications, patents, and applications, or areotherwise known or ascertainable by those of skill in the art from theteachings set forth herein. All of these techniques may be combined withthose of the various embodiments of various aspects of the invention toyield enhanced embodiments. Still other embodiments may be derived fromcombinations of the various embodiments explicitly set forth herein.

FIGS. 4A-4I illustrate various stages in the formation of a single layerof a multi-layer fabrication process where a second metal is depositedon a first metal as well as in openings in the first metal where itsdeposition forms part of the layer. In FIG. 4A, a side view of asubstrate 82 is shown, onto which patternable photoresist 84 is cast asshown in FIG. 4B. In FIG. 4C, a pattern of resist is shown that resultsfrom the curing, exposing, and developing of the resist. The patterningof the photoresist 84 results in openings or apertures 92(a)-92(c)extending from a surface 86 of the photoresist through the thickness ofthe photoresist to surface 88 of the substrate 82. In FIG. 4D, a metal94 (e.g. nickel) is shown as having been electroplated into the openings92(a)-92(c). In FIG. 4E, the photoresist has been removed (i.e.chemically stripped) from the substrate to expose regions of thesubstrate 82 which are not covered with the first metal 94. In FIG. 4F,a second metal 96 (e.g., silver) is shown as having been blanketelectroplated over the entire exposed portions of the substrate 82(which is conductive) and over the first metal 94 (which is alsoconductive). FIG. 4G depicts the completed first layer of the structurewhich has resulted from the planarization of the first and second metalsdown to a height that exposes the first metal and sets a thickness forthe first layer. In FIG. 4H the result of repeating the process stepsshown in FIGS. 4B-4G several times to form a multi-layer structure areshown where each layer consists of two materials. For most applications,one of these materials is removed as shown in FIG. 4I to yield a desired3-D structure 98 (e.g. component or device).

The various embodiments, alternatives, and techniques disclosed hereinmay form multi-layer structures using a single patterning technique onall layers or using different patterning techniques on different layers.For example, different types of patterning masks and masking techniquesmay be used or even techniques that perform direct selective depositionswithout the need for masking. For example, conformable contact masks maybe used on some layers or in association with some selective depositionson some layers while non-conformable contact masks may be used inassociation with other depositions on the same layers or in associationwith depositions on other layers. Proximity masks and masking operations(i.e. operations that use masks that at least partially selectivelyshield a substrate by their proximity to the substrate even if contactis not made) may be used, and adhered masks and masking operations(masks and operations that use masks that are adhered to a substrateonto which selective deposition or etching is to occur as opposed toonly being contacted to it) may be used.

In some embodiments of the invention, masks appropriate for selectivedepositions, etching operations, or other operations that pattern asubstrate may be, for example, formed using a photomask through which aphotopatternable material is exposed and/or via a direct exposure of alaser beam, or the like, which may be scanned (using relative motion),and possibly shuttered on and off, selectively onto desired portions ofthe photopatternable material. After exposure, if necessary, developmentof the photoresist may occur to yield the desired patterning.

Some embodiments of the invention are directed to techniques forelectrochemically fabricating multi-layer three-dimensional structureswhere selective patterning of at least one or more layers occurs via useof a mask that was formed using data representing cross-sections of thethree-dimensional structure which has been modified to place it in apolygonal form which defines only regions of positive area. The regionsof positive area are regions where structural material is to be locatedor regions where structural material is not to be located depending onwhether the mask will be used, for example, in selectively depositing astructural material or in selectively depositing a sacrificial material.The modified data may take the form of adjacent or slightly overlappedrelatively narrow rectangular structures where the width of thestructures is related to a desired formation resolution. The spacingbetween centers of adjacent rectangles may be uniform or may be avariable. The data modification may also include the formation ofduplicate copies of an original structure, scaled copies, mirroredcopies, rotated copies, complementary copies, and/or the like.

FIG. 5 provides a block diagram of a process for forming athree-dimensional structure according to a first embodiment of theinvention including the manipulation of data representing the structureto obtain data suitable for use in creating one or more photomasks thatwill be used in the fabrication of the structure.

The block diagram of FIG. 5 begins with block 100 which calls for theconceiving of a three dimensional structure or plurality of structuresthat one would like to form. The structures may be of any scale;however, the most preferred embodiments of the invention are directed tothe formation of mesoscale or microscale structures (e.g. parts,devices, components, or the like).

Block 110 of the process calls for the development of data that isdescriptive of the structure or structures to be formed. This data maytake a variety of forms, for example, it may be surface data descriptiveof a three dimensional structure, cross sectional data descriptive ofone or more layers making up the structure, or volumetric data definingthe three dimensional structure or structures. Examples of such data canbe found in U.S. Pat. No. 4,961,154 to Pomerantz et al. which isentitled “Three Dimensional Modeling Apparatus”; U.S. Pat. No. 5,184,307to Hull et al. which is entitled “Method and Apparatus for Production ofHigh Resolution Three Dimensional Objects by Stereolithography”; andU.S. Pat. No. 5,321,622 to Snead et al. which is entitled “Boolean LayerComparison Slice”. These patents are hereby incorporated herein byreference as if set forth in full.

Block 120 calls for the manipulation of the supplied data so as toobtain data suitable for generating one or more photomasks which aredescriptive of at least portions of one or more cross-sections of thestructure or structures to be formed. The manipulated data may providemodified definitions of solid and empty regions based on a number offactors. These factors include, for example, the type ofphotopatternable material that will be used, whether or not the maskthat will be produced is intended to produce structural regions (i.e.regions of solid) or sacrificial regions (i.e. hollow regions), whetheror not some form of boundary position offsetting will be used (e.g. toaccommodate for various offsets or shifts in boundary positions that mayresult from the processes used to create the structure or used to createthe mask), whether or not any scaling of the size of the structure willoccur, whether or not any mirroring of structural features will occur,whether or not the complimenting of the data will occur for reasonsother then those noted above, and whether or not the offset betweenadjacent raster or hatch lines will be of a fixed value or will be avariable.

If the photopatternable material is a photoresist of the negative typethe photoresist will become insoluble in those regions where lightsufficiently exposes it whereas if it is of the positive type it willbecome selectively soluble in certain solvents in regions where lighthas exposed it. Thus depending upon the type of photoresist chosen, thedata used to define the exposed regions may need to vary. If on theother hand a contact mask is being made, depending upon the type ofprocess being used (e.g. in one of the processes disclosed in U.S. Pat.No. 6,027,630 as discussed herein above), it may be necessary for theregions defined by the data to be complemented, size shifted, orotherwise adjusted.

Turning back to FIG. 5, block 130 calls for the generation of one ormore photomasks based at least in part on the manipulated data derivedin block 120.

Block 140 calls for the patterning of a masking material (e.g. that willbe used to directly pattern material forming part of the layers of thestructure) using the at least one photomask.

Block 150 calls for the formation of a layer of the structure from oneor more desired materials using patterned masking material obtained inblock 140 where the patterned masking material is used in selectivelydepositing a building material (e.g. a structural material or asacrificial material) and/or to modify a substrate or previouslydeposited material.

Block 160 calls for the formation of any additional layers that arerequired to build the structure while block 170 calls for theperformance of any necessary post layer formation processes (i.e. postprocessing operations) to complete formation of the three dimensionalstructure or structures.

FIG. 6 provides a block diagram detailing an exemplary set of operationsthat may be performed in completing the data manipulation operation ofFIG. 5 including a cross-sectioning operation, an indicating operation,and a data production operation.

The data manipulation process of FIG. 6 begins with the operation ofblock 222 which calls for the receiving of three-dimensional datadescriptive of the structure or structures to be formed. The receiveddata is then manipulated by the operation of block 232 which calls forthe derivation of one or more levels of cross-sectional data based atleast in part on the data descriptive of the three-dimensionalstructure.

Block 242 calls for defining how each region of the cross-sectional datawill be used in producing the final manipulated data that will be usedin generating each photomask associated with a given data level orcross-sectional level.

Block 252 calls for the production of a data set which includes boundarydescriptions of one or more polygonal geometries that will be used ingenerating a photomask. Each of the polygonal geometries is descriptiveof a positive area or a negative area and the same selection of positiveor negative area is made for each polygon.

In one embodiment of the invention, for example, the polygons arerectangular structures which are oriented along a series of closelyspaced raster or vector lines and where the width of each rectangle isselected to provide complete coverage of the region located betweenconsecutive raster lines that is intended to be controlled or covered bythe polygon (e.g. the width is set to be equal to the spacing betweenthe raster lines or somewhat larger then the spacing between rasterlines).

FIGS. 7A-7C provide block diagrams of three examples of how theoperations of FIG. 6 may be supplemented by additional operations toallow photomasks to be produced which have patterning corresponding to aplurality of copies of the structure or structures to be formed.

FIG. 7A introduces an additional operation between operations 222 and232 of FIG. 6. This additional operation 224 calls for the making ofcopies of the three-dimensional data corresponding to any duplicates ofthe 3-D structure that are to be simultaneously formed.

FIG. 7B, on the other hand, calls for the inclusion of an additionaloperation 234-1 between operations 232 and 242 of FIG. 6. Operation234-1 calls for the making of a copy of the cross-sectional data foreach duplicate of the structure that is to be included on the photomask.

FIG. 7C calls for the introduction of an operation 234-2 betweenoperations 232 and 242 of FIG. 6. Operation 234-2 calls for theproviding of offsets and links to cross sectional data for any structureor structures that are to be duplicated as opposed to making a duplicateof the entire data set of the structure or structures for each copy tobe produced. It is intended that the link and offset information reducethe amount of data storage required and computational effort necessaryto produce the data sets called for in block 252.

In alternative embodiments the copies and or offsets and links of FIGS.7A-7C may alternatively, or additionally, include variations in thecopies or additional parameters in the links and offsets so as to callfor variations of the original structure or structures to be produced.As noted previously such variations may include scaling, boundaryoffsetting, mirroring, complementing, and/or the like.

FIG. 8 provides a block diagram showing two examples of how theindicating operation of FIG. 6 may be implemented.

Block 242-1 of FIG. 8 provides a first example implementation ofoperation 242 of FIG. 6. It calls for the regions outside of thepositive area boundaries to be non-data producing regions. In otherwords, the positive areas are the areas which will give rise to polygonsthat will be included in the data set produced by operation 252.

Block 242-2 calls for the regions outside the positive area boundariesto be data producing and regions within the positive boundaries to benon-data producing. In other words, the polygons produced in theoperation of block 252 will include mask regions that are exclusive ofregions defined by the positive boundaries of the cross-sectional dataof block 232. In other alternative embodiments, it may be possible toprovide other definitions of how positive and/or negative areas shouldbe handled. For example, in embodiments where more then twocomplimentary materials will be used during the formation of a structureor structures, the definitions may be based upon material type as wellas upon whether a boundary defines a positive or negative region.

FIG. 9 provides a block diagram showing an example of how the dataproduction operation of block 252 of FIG. 6 may be implemented alongwith two example alternatives on how polygon boundaries may be relatedto the data lines from which they are derived in this example.

The data production operation of block 252 may be implemented by firstderiving a plurality of spaced data lines located within the regionsthat are defined to be data producing as called for by block 254 of FIG.9. These spaced data lines may be called hatch lines, fill lines, rasterlines, or the like and are located within in the data producing regions.These lines may be derived conceptually from the overlaying of the dataproducing regions onto a predefined grid of hatch paths, fill paths, orraster paths (i.e. locations capable of producing lines to the extentthey are located within data producing regions) or alternativelylocations of the paths may be defined in a more geometry sensitivemanner. Such sensitivity may result in the spacing of paths beingreduced or increased based on an intercept angle between approximatepath locations and one or both of the boundaries of the data producingregions.

In alternative embodiments, the orientation of hatch paths may be variedfrom cross-section to cross-section or even from cross-sectional regionto cross-sectional region, for example, in order to minimize anynegative effects that quantization resulting from the use of rasterlines in generating rectangular polygons (i.e. pseudo-raster polygons orsimply pseudo-rasters). Various methods for producing the spaced datalines are taught in U.S. Pat. Nos. 5,184,306 and 5,321,622 which havebeen discussed above and which are incorporated herein by reference.

Block 256 calls for the conversion of each spaced data line into apolygon whose length is defined by the length of the data line itselfand whose width and position may be defined in different ways. Forexample, as indicated in block 258-1 the position of the polygon may becentered about the data line while the width of the polygon may be equalto that of the spacing between the data lines (block 260-1) or it may beequal to the spacing between the data lines plus an incremental amount(block 260-2). Alternatively as indicated in block 258-2 the positionmay be bounded on one side by the data line that gives rise to thepolygon while the width is set to that of the line spacing (block 260-1)or is set to the line spacing plus an incremental amount (260-2). Inalternative embodiments, it may be possible to use polygons that are notrectangles. For example, it may be possible to use trapezoids. In otheralternative embodiments, it may be possible to reduce the quantity ofpseudoraster data by merging smaller rectangles together so as toproduce larger rectangles or even more complex polygonal shapes. Suchmerging may occur, for example, when two or more adjacent pseudo rasterrectangles have common end points.

In still other embodiments each polygon may be derived from data linesor portions of data lines located on two consecutive hatch paths wherethe end segments of the polygons are generated from an appropriatebridging of the data lines. In the simplest of cases, the bridging ofthe data lines may produce polygon boundary lines from lines thatconnect the hatch lines endpoint to endpoint or beginning point tobeginning point. In other cases, it may be desirable to use informationconcerning common positioning of the data lines in determining whetheror not bridging should occur. In still other cases it may be desirableto consider whether or not multiple lines exist on one hatch path thatoverlay positions occupied by a single hatch line on an adjacent hatchpath. In still other embodiments, it may be desirable to base thepositioning of ambiguous bridging elements based on continuity ofbridging element slope from one or more adjacent pairs of data lines.

FIG. 10 provides a schematic illustration of a top view of an examplecross-sectional configuration of two three-dimensional structures thatare to be formed.

The sample cross-section shown in FIG. 10 includes a first structure 302having two boundary elements 304 and 306 which define a region ofstructure 308 and a hollow region or empty region 310. Structure 312includes a boundary region 314 and a region of structure 318.

FIGS. 11A-11D provide schematic illustrations of top views of variousstages of the process of FIG. 9 where the regions defined to be dataproducing are those that are occupied by structure to be formed.

FIG. 11A depicts a state of the process after boundary regions 304, 306,and 314 have been created. Boundary 304 defines a positive area with theexception of the region occupied by boundary 306 which defines anegative area. Boundary 314 also defines a positive area.

FIG. 11B depicts a state of the process after raster lines 324 have beenmade to occupy a region defined by the Boolean difference betweenboundaries 304 and 306 and hatch lines 334 have been made to occupyboundary 314.

FIG. 11C depicts the state of the process where only the hatch lines orraster lines are shown.

FIG. 11D depicts a state of the process after hatch or raster lines 324and 334 have been converted to rectangular polygons 326 and 336. Thelength of each polygon corresponds to the length of the hatch or rasterline which gave rise to it while the width, w, of the polygonscorrespond to the spacing, w, between adjacent hatch paths or rasterpaths. To distinguish the separate polygons, adjacent polygons have beendepicted with alternating fill patterns.

FIG. 12 provides a schematic illustration of a top view of the structureof FIG. 11A where the polygons are shown as having a width that issomewhat larger than the spacing between successive polygons. FIG. 12depicts transition regions 328 and 338 that are located at theboundaries separating adjacent polygons. These transition regions areactually regions of overlap between adjacent polygons which result fromthe width of each polygon, w′, being greater then the separation, w,between consecutive raster paths.

FIGS. 13A-13D provide schematic illustrations of top views of variousstages of the process of FIG. 9 where the regions defined to includepositive areas are those that are outside the regions to be occupied bystructure to be formed.

FIGS. 13A-13D depict complementary patterns as compared to those ofFIGS. 10, 11B, 11C and 11D respectively. Boundaries 404, 406, and 414are similar to boundaries 304, 306 and 314 with the exception that theyare defined to enclose areas of opposite sign.

FIG. 13A also depicts the conceptual existence of a fourth boundary 416which encloses the effective build area or area of the photomask.Boundary 416 is considered to define a positive area.

FIG. 13B depicts a state of the process after hatch or raster paths havegiven rise to hatch or raster lines in the regions of positive area(i.e. regions defined to be data producing). A comparison of FIGS. 13Band 11B indicate that the reversed definitions of areas defined by eachboundary type and inclusion of a global boundary 416 have resulted inFIG. 13B producing a complementary pattern of hatch lines to those ofFIG. 11B. The complementary pattern of hatch lines is shown more clearlyin FIG. 13C as boundaries have been removed.

FIG. 13D depicts a state of the process after hatch lines have beenconverted to a polygon or pseudo-raster volumes where the length of thepolygons is based on the length of the hatch lines that gave rise tothem and the width of the polygons is set to be equal to the width, w,of the spacing between hatch paths.

FIGS. 14A-14B provide schematic illustrations of top views of a pair ofstructures which are to be duplicated multiple times in a mask that isto be produced, where the duplications may include one or more ofrotations, scaling variations, mirroring operations, complementingoperations, and the like.

FIG. 14A graphically depicts the contents of a data file that may beused in producing a photomask. The data file includes structures 420 and422 defined by a plurality of pseudo-rasters for structures 420 and 422and for a plurality of duplicates of them. The data provides forproduction of a photomask that represents an array of structures. Thephotomask may in turn be used to produce a patterning mask which cangive rise to an array of structures during build operations.

FIG. 14B depicts an alternative data set where structures 420 and 422have been duplicated, scaled, mirrored and rotated and complemented, soas to give rise to a data set that may be used to produce a photomaskwith a plurality of different configurations of a basic structure orstructures that may be used in forming the plurality of differentstructures simultaneously in a single build process.

FIG. 15 provides a block diagram of a process for forming athree-dimensional structure according to a second embodiment of theinvention including the manipulation of data representing the structureto obtain data suitable for use in creating one or more masks that maybe used in selectively patterning a substrate or previously depositedmaterial during the fabrication of the structure.

The process of FIG. 15 is similar to that depicted in FIG. 5 with theexception that the process of FIG. 15 does not produce data that is usedto produce a photomask but instead uses the produced data to pattern amasking material that will be directly used in patterning a substrate ordepositing a material thereto. The direct patterning of a maskingmaterial may occur, for example, by selective scanning of a laser beamover the surface of the masking material wherein different scanningspeeds may be used to obtain different levels of exposure or where theintensity of the laser beam striking the surface may be modulated on andoff depending on whether the beam is directed to a location whereexposure is to occur. The exposure from the laser beam may result in theformation of a latent pattern which can be brought out by developing thematerial (e.g. a photoresist material) or alternatively the exposure mayresult in the ablation of material.

Other direct patterning techniques might involve the selectivedeposition of patterning material onto the surface of the substrate orpreviously formed layer, for example, by controlled ink jet dispensingor the like. The operations of blocks 400, 410 and 420 are similar tothe operations of blocks 100, 110, and 120.

Block 440 calls for the patterning of a masking material using themanipulated data.

Blocks 450, 460, and 470 call for similar operations to those set forthin blocks 150, 160 and 170.

Various other embodiments of the present invention exist. Some of theseembodiments may be based on a combination of the teachings herein withvarious teachings incorporated herein by reference. Some embodiments maynot use any blanket deposition process and/or they may not use aplanarization process. Some embodiments may involve the selectivedeposition of a plurality of different materials on a single layer or ondifferent layers. Some embodiments may use selective depositionprocesses or blanket deposition processes on some or all layers that arenot electrodeposition processes. Some embodiments may use nickel as astructural material while other embodiments may use different materials.Some embodiments may use copper as the structural material with orwithout a sacrificial material. Some embodiments may remove asacrificial material while other embodiments may not. In someembodiments the anode (used during electrodeposition) may be differentfrom a conformable contact mask support and the support may be a porousstructure or other perforated structure. Some embodiments may producestructures that include both conductive materials and dielectricmaterials.

Some embodiments may produce pseudo raster data representing regionsthat are different from cross-sectional regions or selected materialregions associated with specific cross-sections. Some processes mayemploy mask based selective etching operations in conjunction withblanket deposition operations. In such processes, pseudo-rasters may begenerated based on desired etching patterns or patterns of mask openingsthat will be used in association with such etching operations. Someembodiments may form structures on a layer-by-layer basis but maydeviate from a strict planar layer by planar layer build up process infavor of a process that interlacing material deposited in associationwith different layers. Such alternative build processes are disclosed inU.S. application Ser. No. 10/434,519, filed on May 7, 2003, entitledMethods of and Apparatus for Electrochemically Fabricating StructuresVia Interlaced Layers or Via Selective Etching and Filling of Voids.This application is hereby incorporated herein by reference as if setforth in full.

In view of the teachings herein, many further embodiments, alternativesin design and uses of the invention will be apparent to those of skillin the art. As such, it is not intended that the invention be limited tothe particular illustrative embodiments, alternatives, and usesdescribed above but instead that it be solely limited by the claimspresented hereafter.

1. A process for forming a multilayer three-dimensional structure fromat least one structural material and at least one sacrificial material,comprising: (a) providing a substrate; (b) depositing a first materialon the substrate, which is either a structural material or a sacrificialmaterial; (c) depositing a second material on the substrate to regionsnot occupied by the first material, wherein the second material is theother of the structural material or the sacrificial material; (d)planarizing the first and second materials to define a surface of thefirst layer; (e) repeating the operations of steps (b)-(d) a pluralityof times to form a plurality of successive layers wherein eachsuccessive layer is formed on and adhered to a previously formed layer;(f) after formation of the plurality of layers, removing the sacrificialmaterial from the structural material on a plurality of layers such thatthe structure, comprising the structural material, is released from thesacrificial material; wherein the process additionally comprises: (g)providing cross-sectional data descriptive of a plurality ofcross-sections of the three-dimensional structure; (h) processing thecross-sectional data to derive modified cross-sectional data comprisingpolygons, where each individual polygon encloses only a positive area;(i) using the modified cross-sectional data during formation of at leastone of the layers of the three-dimensional structure.
 2. The process ofclaim 1 wherein the providing cross-sectional data comprises: (j)providing data descriptive of the three-dimensional structure; and (b)processing the data to derive cross-sectional data descriptive of aplurality of cross-sections of the three-dimensional structure.
 3. Theprocess of claim 1 wherein the using the modified cross-sectional datacomprises using the modified cross-sectional data in a process forforming a patterned adhered mask that is used during the formation of atleast one layer.
 4. The process of claim 1 wherein the depositing of thefirst material during the formation of a layer comprises selectivelydepositing the first material.
 5. The process of claim 1 wherein thedepositing of the first material during the formation of a layercomprises selective etching a void into the substrate or previouslydeposited material.
 6. The process of claim 1 wherein the processing ofthe cross-sectional data comprises deriving a plurality of adjoiningrectangular structures.
 7. The process of claim 6 wherein therectangular structures are laid out with their lengths extending along aseries of parallel lines.
 8. The process of claim 7 wherein the parallellines are spaced from consecutive lines by a width and a width of therectangles is equal to the width between the consecutive lines.
 9. Theprocess of claim 7 wherein the parallel lines are spaced fromconsecutive lines by a width and a width of the rectangles is greaterthan the width between the consecutive lines.
 10. The process of claim 7wherein the parallel lines are spaced from consecutive lines by a widthand a width of the rectangles is less than the width between theconsecutive lines.
 11. The process of claim 7 wherein the parallel linesare spaced from consecutive lines by a width which is a variable. 12.The process of claim 11 wherein the variable width is automaticallyselected by a predefined algorithm which is at least in part based on anangle of contact between a boundary line and a line collinear with alength of the rectangle.
 13. The process of claim 1 wherein the polygonsdefine regions where material forming part of the structure is to belocated.
 14. The process of claim 1 wherein the polygons define regionswhere material forming part of the structure is not to be located. 15.The process of claim 1 wherein the polygons define regions which havebeen boundary compensated.
 16. The process of claim 3 wherein the maskdefines multiple copies of the structure to be formed.
 17. The processof claim 14 wherein the processing of the cross-sectional data for atleast one copy of a structure to be formed, comprises processing of linkdata and attribute data, wherein the link data provides access to asingle copy of the data specific to an existing structure and whereattribute data comprises one or more of (1) location data for placementof the copy, (2) offset data for placement of the copy, (3) rotationalinformation for orienting the copy, (4) mirroring information forconfiguring the copy, and/or (5) scaling information for sizing thecopy.
 18. The process of claim 14 wherein a least one of the multiplecopies is defined as a complementary pattern of at least one of (1) across-section of the structure to be formed, (2) a scaled version of across-section of the structure, (3) a mirrored version of across-section of the structure, or (4) a boundary compensated version ofthe structure.
 19. The process of claim 3 wherein the using of themodified cross-sectional data comprises using the modified data toproduce at least one photomask that is used in a process for forming apatterned adhered mask.
 20. The process of claim 3 wherein the using ofthe modified cross-sectional data comprises using the modified data tocontrol a relative motion of a scanning laser beam and a mask materialto form a patterned adhered mask.
 21. A process for forming a selectivepattern of deposited material, comprising: (a) providing cross-sectionaldata descriptive of a patterned deposit to be formed; (b) processing thecross-sectional data to derive modified cross-sectional data comprisingpolygons, where each individual polygon encloses only a positive area;(c) using the modified cross-sectional data during formation of theselective patterning of deposited material; (d) providing a substrate;and (e) depositing and patterning the material on the substrate.